Electric switch



June 17 ,-1924.

' G. A. BURNHAM ELECTRIC SWITCH 2 Shasta-Sheet Filed April 16 1920 r T.I

June 17, 1924. 1 1,498,507

G. A. BURNHAM ELEcTnc swI'TcH Filed April 16, 192() 2 Sheets-Shed?. 2

Patented June 17, 1924.

UNITED STATE-sY PATENT OFFICE.

GEORGE A. BURNHAM, OF SAUGUS.. MASSACHUSETTS, ASSIGNOR TO SEARS B.CONDIT, OE BROOKLINE, MASSACHUSETTS.

ELECTRIC SWITCH.

Application led April 16, 1920. Serial No. 374,278.

To all whom t 'may concern:

Be it known that I, GEORGE A. BURNHAM,

a citizen of the United States, residing at Saugus, in the county ofEssex and State of Massachusetts, have invented an Improvement inElectric Switches, ot which the following is a specification. i

This invention relates to electric switches especially adapted safely tointerrupty alterl0 nating current of high value.

In another application, Serial #309,853, tiled July 10, 1919 whichapplication. has issued as Patent l\o. 1,413,156, under date of April18, 1922,'I have described a switch having means comprising aresiliently sup,- ported oil receptacle to absorb energy developed uponcircuit interruption and arranged freely to vent between the oilreceptacle and the switch-supporting frame comprising the cover for theoil receptacle when a pressure develops therein of a. value sufficientto ioicethe receptacle away from the cover.

It is an object ot this invention to arrange the resiliently mounted oilreceptacle to bein substantially gas tig-ht contact with the cover atall times, or at least for the greatest part of its extent ot movementdownward, so that the switch in this respect is gas tight as vthis termis applied to switches of this general type, or the contact between theoil receptacle and the switch frame is as gas tight VVas in the ordinarytype ot non-resiliently mounted oil receptacle. However, due toirregularities in the walls ot the reccptacle and switch frame, thecontact is imperfect and the switch is suticiently vented to permit itto breathe; that is, admitot efflux and iniiux of aiiI between theexpansion space of the switch and the atmosphere occasioned bytemperaturevariations. In addition, I may provide the switch with aseparate vent.y

In certain types of oil immersed switches it is not practicable, byreason oil size or structural conditions, removably and yieldingly tosupport the oil receptacle from the fixed switch frame and a furtherobject of the invention is resiliently and, preferably, also removablyto support the oil receptacle in position by means independent of Vtheswitch frame.

In carrying out this object of the invention I mount the oil receptacleyieldingly in a carriage positioned beneath the switch by which the oilreceptacle is retained in position and as a further object of theinvention, for removing the oil receptacle, I provide means by which thereceptacle may be raised and iowered in the carriage and removed fromthe switch; and the carriage, with or without the oil receptacle isarranged to be moved from position beneath the switch.

A further object is generally to improve the construction and operationof an oil immersed switch.

Fig. 1 is a side view, partly broken away, of anoil immersed switchembodying my invention.

Fig. '2 is a of Fig. 1.

Fig. 3 is a transverse sec-tional elevation of the switch.

Fig. Lisa partial vertical section similar to Fig. 3 but'illustratingthe oil receptacle in a downwardly moved position. Y Fig. 5 is a sideelevation, partly in section, of an embodiment of .the invention whereasthe oil receptacle is resiliently supported in position independently ofthe switch frame on a carriage having seltcontained raising and loweringmeans,

Fig. 6 is a plan detail of the raising and lowering means. Y

As here shown the oil immersed switch partial plan view of the switch,embodying my invention includes the fixed switch frame 10 comprising acover Vtor the oil receptacle 11 and having the peripheral iiange orapron 12 enclosing the side wall of the oil receptacle and depending fora considerable distance over said wall, and the arm 13 by which theswitch `frame is adapted to be `fixed to a support, thereby to supportthe switch.

Movable and stationary switch members 14: and l5 are carried by said'frame and depend therebelow into the oil adapted to be contained insaid oil receptacle.

The oil receptacle 11 is contained within and, preferably, supportedupon the bottoni of the outer receptacle or spill tank 16 which has itsside wall peripherally spaced from the inner oil receptacle 11 toprovide a space for the collection of oil discharged fromV the innerreceptacle upon certain conditions caused by circuit interruption, andextended upwardly toward, and preferably above the depending flange orapron 12 of the cover and having an open top for the escape ofuncondensed oil or other gas or vapor.

F or certain purposes the two receptacles may be united as by spotwelding the bottoms together, andfor other purposes the receptacle maynot be united and the inner receptacle may simpl-y rest within the outerreceptacle.

It is to be noted that the space between the side walls of the tworeceptacles is relatively deep and narrow by which construction it isexceedingly difficult to support combustion of oil in the outerreceptacle, whereby the lire hazard is materially decreased.

rlChe receptacles are suspendedV from the switch Yframe on rods 17 hxedin lugs 1S of said frame and extended through apertured lugs 19 of theouter receptacle 16 and through apertures in the supporting platforms orgrids 20. The lower ends of said rods are threaded and compressionsprings 2l are arranged thereon and engage said grids 2O and the nuts 22removably threaded on the ends of said rods, whereby the oil receptacleis yieldingly and also removably supported in position from the switchframe.

In'certain instances the outer receptacle 16 may be dispensedr with andthe inner receptacle supported directly by the structure above setforth.

Whereas, in the above-named co-pending application the oil receptacle isspaced from the apron of the switch frame whereby to provide a passagethrough which the switch is vented, it is an object of the presentinvention so to arrangeV the switch that the side walls of the oilreceptacle and the apron are in general peripheral contact, and yet theengagement should not be so tight as to restrict the downward movementof the oil receptacle when a sufficient pressure is developed therein. Apressure within the switch serves, to a greater or less degree, toexpand the somewhat resilient side walls of the receptacle and tends toforce it against the apron. Due, however, to the irregularities in thewall of the oil receptacle and the switch frame there will be suflicientclearance at various points'to permit the switch to breathe, yet theswitch will not be' a ventedv switch as the term is commerciallyapplied. Y

The top edge of the oil receptacle is adapted normally to seat againstthe switch frame comprising' its cover.`

Under normal conditions of switch operation the oil receptacle will beheld against the switch frame by its springs. When, however, a pressureis set up within the switch, as by the ignition of combustible gases inthe gas expansion space a under the cover, or otherwise, due to theinterruption of a heavy load, pressure Vwill build up faster than it canbe vented and the oil receptacle will be forced downward, thereby tokeep down the pressure. Moreover, the resiliently supported oilreceptacle absorbs energy due to circuit interruption, or the shock ofthe explosion, and thereby prevents damage to the switch. Theconstruction of the switch is such as to provide a movable member whosechief purpose is to absorb the shock of circuit interruption, or one inwhich the energy may be stored, subsequently to be gradually dissipated.

Whereas in Figs. 1 through 4, I have illus-V trated the oil receptacleas resiliently supported from the fixed switch frame, in Fig. 5, I haveillustrated means for resiliently supporting the receptacle in positionabout the switch-members independent of the switch, by which myinvention is particularly adapted for certain type of switches.

In carrying out this embodiment of my invention, I provide a truck orcarriage for the oil receptacle having the wheels 30 by which thecarriage may Vbe moved and the four uprights or standards 31 and 32. Aplatform 33 having the receptacle receiving recess 34 therein and thecorner lugs 35 is slidably received on and is guided for verticalmovement by said standards. The oil receptacle of the switch is adaptedto be received in said recess with the side walls thereof holding thereceptacle against lateral displacement, and yielding means as springs36 are interposed between the bottom of the receptacle and the tableupon which the oil receptacle is adapted to rest and by which it isresiliently and yieldingly supported.

Raising and lowering means are associated with the carriage by which thereceptacle may be raised to and lowered from position, and in itslowered position, the carriage with the receptacle may be moved awayfrom the switch.

For this purpose the two opposite corner standards 32 arescrew-threaded, and worm gears 37 having screw-threaded bores aredisposed thereon beneath the platform 32 and may serve to support it inset position without the necessity of other holding means. Luge 38depend from the under side of the table 33 and the operating shaft 39 isjournaled therein. vWorms 40, in engagement with said worm gear 37, arefixed to said shaft whereby said worm gears may be simultaneouslyoperated to raise and lower the table and the oil receptacle sup` Theouter oil receptacle 16 is provided on opposite sides with `the handle45 by which the receptacle may be removed from the supporting carriageor otherwise manipulated.

1. An electric switch having an oil receptacle movable in response topressure conditions within the switch due to circuit interruption andmeans to maintain the switch substantially gas tight during circuitinterruption comprising a fixed switch frame comprising a cover for theoilrecep-V tacle having a peripheral depending apron adapted to bemaintained in general peripheral contact with the side wall of thereceptacle in moved positions thereof.

2. An electric switch having a component movable in response to pressureconditions within the switch and means to maintain said switchsubstantially gas tight during such movement comprising a relativelymovable receptacle and a switch frame comprising a cover for saidreceptacle, said frame having a depending apron adapted to be maintainedin general peripheral contact with the side wall of the receptacle inrelatively moved positions of the frame and receptacle. n

3. An electric switch comprising a fixed switch frame, switch memberscarried thereby, an oil receptacle adapted to contain said switchmembers, and means independent of the switch to hold said receptacleyieldingly in position.

4. The combination of an electric switch having a fixed switch frame, anoil receptacle, and a plat form adapted to receive the oil receptacleand support it in position independently of the switch, and means toadmit of raising and lowering the platform and receptacle into and outof position beneath the switch frame.

5. The combination of an electric switch having a fixed switch frame andan oil receptacle, and a movable carriage adapted to receive the oilreceptacle and support it in position independently of the switchadmitting of raising and lowering the receptacle into and out ofposition and having means to admit of moving the carriage and oilreceptacle as a unit away from the switch.

6. rEhe combina-tion of an electric switch having a fixed switch frameand an oil receptacle, a supporting platform for the oil receptacle andyielding means interposed between the oil receptacle and platform.

7. The combination of an electric switch having a fixed switch frame andan oil receptacle, a supporting platform for the oil receptacle andsprings interposed between the oil receptacle and platform upon whichthe oil receptacle is adapted to rest.

8. The combination of an electric switch having a fixed switch frame andan oil guiding means.

10. The combination of an electric switch having a fixed switch frameand an oil receptacle, and a supporting carriage for the oil receptacleincluding receptacle receiving means, and raising and lowering means forthe receiving means.

11. The combination of an electric switch having a fixed switch frame,and an oil receptacle, and a receptacle-receiving and supportingcarriage comprising vertical uprights, a receptacle-supporting platformmovable on said uprights and means to raise and lower said platform onsaid uprights.

12. The combination of an electric switch having a fixed switch frame,and an oil receptacle, and a receptacle-receiving andsupporting-carriage comprising vertical uprights, areceptacle-supporting platform movable on said uprights, resilient meanscarried by said platform adapted to receive the` receptacle, and meansto raise and lower said platform on said uprights.

13. An oil receptacle supporting-device for electric switches comprisinga carriage, and a receptacle-supporting platform vertlcally movable insaid carriage.

14. rin oil receptacle supporting-device for electric switchescomprising a carriage and a receptacle-supporting platform verticallymovable in said carriage having yielding means adapted to receive thereceptacle.

lfAn oil receptacle supporting-device for electric switches comprising acarriage adapted to receive and yieldingly support the receptacle havingmeans to raise and lower the supported receptacle.

16. An oil receptacle supporting-device for elect-ric switchescomprising a carriage having uprights, a platform movable on saiduprights having a receptacle receiving recess, springs arranged in saidrecess adapted to support the receptacle, and means to aise and lowersaid platform on said uprights adapted to hold it in set position.

17. An electric switch comprising a fixed switch frame having aperipheral depending' apron, an oil receptacle adapted to contain oil inwhich the' switch members are immersed received wit-hin said apron, asecond receptacle containing said oil receptacle having its side wallsspaced from the side walls of the cil receptacle adapted to catch cilexpelled from the oil receptacle between it and said apron, and meansindependent of the switch to support said second recepmele in position.'Y

18. An electric switch comprising a iixed switch freine, an innerreceptacle adapted to contain oil, in which the switch members' areimmersed and remove-bly disposed beneeth said heme, and an outerreceptacle supporting and containing seid oil receptaaie to catch oilexpelled from said oil recept-noie, said outer receptacle having manu'-211 engaging means by which the two receptacles may be moved.

In testimony whereof, I have signed my name to thisspeoioabion. Y

GEGRGE A. BURNHAM.

